Ruminants are hoofed, even-toed mammals of the suborder Ruminantia that have a stomach divided into four compartments and that chew a cud consisting of regurgitated, partially digested food. Well known ruminants include cattle, sheep, goats, deer, and giraffes. Of this group, the most important to man are cattle, sheep, and goats because they are raised as livestock for home use and profit around the world.
The diet fed to ruminant livestock is important because it has a major effect on the animal's growth rate, body composition, and, in the case of mature females, milk production. Within the past several decades, the supplementation of plant feed with various micronutrients has become more common. A large number of feed supplements for ruminants have been disclosed.
Chromium is a metallic element of atomic number 24 that has been used a feed supplement. In a 1996 article entitled "Effects of Chromium Supplementation on Early Lactation Performance of Holstein Cows" published in the Canadian Journal of Animal Science, W. Z. Yang et al. report that supplementing the diet of Holstein cows with an amino acid-chelated chromium compound increased milk yield. The authors discuss several possible reasons for the increase. First, the chromium may increase glucogenic capacity. Second, the chromium may alter glucose metabolism by altering insulin sensitivity. And third, the chromium may play a role in reducing gluconeogenesis from amino acids.
The use of other chromium compounds as feed supplements is disclosed in Wolfram et al., U.S. Pat. No. 4,326,523, issued Apr. 27, 1982 (subcutaneous implants); Howard, U.S. Pat. No. 4,335,116, issued Jun. 15, 1982 (organo-metallic complexes); and Ashmead et al., U.S. Pat. No. 5,614,553, issued Mar. 25, 1997 (amino acid chelates).
Tock et al., U.S. Pat. No. 5,637,312, issued Jun. 10, 1997, disclose the use of sodium formate NaOOCH as a feed supplement for ruminants. Tock et al. state the formate salts stimulate certain beneficial microorganisms in the rumen. These microorganisms are able to break the beta linkages between glucose molecules in cellulose roughage, a major portion of the diet of ruminants. The free glucose molecules are then converted by enzymes to volatile fatty acids which, in turn, are further digested. In short, the addition of sodium formate improves ruminant weight gain and milk production by enhancing the digestibility of cellulose roughage.